1. Field of the Invention
Methods used to synthesize tetrazoles vary widely depending on the availability of the starting reagents and the structure of the final product desired. It has now been discovered that 1,5-disubstituted tetrazoles, which are valuable intermediates leading to useful antibacterial agents, can be prepared from the reaction of an imino sulfonate, synthesized through the reaction of an appropriate amide and a sulfonyl chloride, with a source of azide ion.
2. Description of the Art
Tetrazoles, the physical and chemical properties and synthesis thereof, have recently been reviewed by F. R. Benson in "Heterocyclic Compounds," Vol. 8, R. C. Elderfield, Ed., John Wiley and Sons, Inc., New York, N.Y., 1967, Chapter 1.
Sinnema, et al., Rec. trav. chim., 76, 949 (1957) reports the preparation of 5-phenyltetrazole by the azide displacement of the ethoxy moiety of ethyl benzimidate, while the synthesis of 1,5-disubstituted tetrazoles from the corresponding imino chloride and sodium azide is reported by Schroeter, Ber., 42, 3356 (1909), Smith, et al., J. Am. Chem. Soc., 80, 4647 (1958) and Vaughan, et al., J. Org. Chem., 23, 1909 (1958). Synthesis of mono- and disubstituted tetrazoles by the reaction of an imino chloride with hydrazoic acid in an aromatic solvent is taught by Harvill, et al., J. Org. Chem., 15, 662 (1950) and Fallon, et al., J. Org. Chem., 22, 933 (1957).